title: pH-regulated release of dopamine from well-ordered self-assembled monolayers: electrochemical studies.
abstract: In the present work, gold electrode modified with novel aldehyde-terminated self-assembled monolayers (SAMs) was used for controllable load and release of dopamine molecules by pH triggering. Electrochemical techniques including cyclic voltammetry (CV) and electrochemcial impedance spectroscopy (EIS) were employed to investigate the SAMs characteristic on the gold electrode surface. The electrochemical experiments indicated Faradaic behavior for the electrode surface after its modification with dopamine. Notably, it was observed that decreasing the conditioning pH, results in a decrease of peak currents, presumably due to the hydrolysis of the terminal imine bonds and releasing the dopamine moiety into the solution. Moreover, the preliminary kinetics studies were done for dopamine release from the SAMs surface as a model to design future drug delivery systems. Finally, the rate constant of dopamine release from the SAMs modified surface estimated to be 0.167 day(-1) at pH=3.
authors.affiliation: Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran. Electronic address: habibkazemi@iasbs.ac.ir.
authors.forename: Sayed Habib
authors.initials: SH
authors.lastname: Kazemi
authors.forename: Abdolhamid
authors.initials: A
authors.lastname: Alizadeh
authors.forename: Rahim
authors.initials: R
authors.lastname: Mohamadi
authors.forename: Mohammad Mahdi
authors.initials: MM
authors.lastname: Khodaei
authors.forename: Davood
authors.initials: D
authors.lastname: Kordestani
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D058266:Dielectric Spectroscopy; D004298:Dopamine / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000447:Aldehydes; D013438:Sulfhydryl Compounds; D006046:Gold; D004298:Dopamine
keywords: Dopamine; Drug release; Self-assembled monolayers; pH triggering